From 23e47b0a60647e247a9c6cc3d578f6f471b3c735 Mon Sep 17 00:00:00 2001
From: Dean Attali <daattali@gmail.com>
Date: Wed, 5 Jun 2024 22:31:16 -0400
Subject: [PATCH] ExtendedTask: add example to docs

---
 R/extended-task.R | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/R/extended-task.R b/R/extended-task.R
index 659a41f471..f03958d569 100644
--- a/R/extended-task.R
+++ b/R/extended-task.R
@@ -41,6 +41,45 @@
 #'   is, a function that quickly returns a promise) and allows even that very
 #'   session to immediately unblock and carry on with other user interactions.
 #'
+#' @examplesIf rlang::is_interactive()
+#'
+#' library(shiny)
+#' library(bslib)
+#' library(future)
+#' plan(multisession)
+#'
+#' ui <- page_sidebar(
+#'   sidebar = sidebar(
+#'     input_task_button("recalc", "Recalculate")
+#'   ),
+#'   textOutput("outval")
+#' )
+#'
+#' server <- function(input, output) {
+#'   rand_task <- ExtendedTask$new(function() {
+#'     future({
+#'       # Slow operation goes here
+#'       Sys.sleep(2)
+#'       runif(1)
+#'     }, seed = TRUE)
+#'   })
+#'
+#'   # Make button state reflect task.
+#'   # If using R >=4.1, you can do this instead:
+#'   # rand_task <- ExtendedTask$new(...) |> bind_task_button("recalc")
+#'   bind_task_button(rand_task, "recalc")
+#'
+#'   observeEvent(input$recalc, {
+#'     rand_task$invoke()
+#'   })
+#'
+#'   output$outval <- renderText({
+#'     rand_task$result()
+#'   })
+#' }
+#'
+#' shinyApp(ui, server)
+#'
 #' @export
 ExtendedTask <- R6Class("ExtendedTask", portable = TRUE, cloneable = FALSE,
   public = list(